Fictional quotes are one of my favorite tools, especially to build characters/groups before they get introduced properly; from the first chapters of my comic:
"We are proud to claim that since its creation, our London has been one of the few self-governing sectors in The City " ~NLU History Club
"Although smaller changes are possible, a constantly shifting sky such as those depicted in the ruins deep below have been proven impossible, as surely nothing would survive such cataclysm..." ~Astrologers consensus, year 872
"These chassis are the remains of ancient creatures, which once roamed the vast reaches of The City. Now they seldom leave their nests..." ~NLU History Club
Crypticals text or even encoded ones are also fun. Even if they're just in binary.